Weight and valve stem assemblies



Nov. 6, 1956 w. LIGILL WEIGHT AND VALVE STEM ASSEMBLIES Filed June 1,1955 FIG. I

INVENTOR.

- WQ THU. 4/14 United States Patent WEIGHT AND VALVE STEM ASSEMBLIESWalter L. Gill, Redlands, Calif.

Application June 1, 1955, Serial No. 512,530

Claims. (Cl. 13738) This invention relates to a weight and valve stemassembly comprising a tipping weight and valve stem actuated thereby andto improved means for assembling and uniting the said weight and valvestem.

The purposes and advantages of the invention will be best understood byreference to the accompanying drawing wherein:

Fig. 1 is a vertical sectional view showing the tipping weight and thevalve stem in upright position and in connection with a vent plug casinghereinafter described;

Fig. 2 is a partial sectional view of thevent plug casing with which thevalve and weight coact, and with the structure and casing in tippedposition;

Fig. 3 is a magnified side view of the metallic part of the valve stem;and

Fig. 4 is a magnified vertical sectional view of the complete rubber andmetallic assembly comprising the valve stem proper.

Like numerals designate corresponding parts in all of the figures of thedrawings.

In the drawings 5 designates the casing of a vent plug for wet storagebatteries, and especially airplane batteries. Since airplane batteriesare, in use, tilted to varying angles in all directions and are sometimes completely inverted, it is common practice to provide them withvalved vent plugs so constructed as to permit the escape of gas duringthe upright or only slightly tipped position of the battery but arrangedto prevent the escape of the electrolyte upon tipping of the batterybeyond a predetermined degree.

The present application relates specifically to the tipping weight andits stem. This structure is of general application. T 0 show that suchis the case the assembly of this invention is illustrated in Fig. 1 inconjunction with a single valve seat on the vent plug casing while inFig. 2 it is illustrated in conjunction with a casing with a high andlow pressure valve arrangement wherein a small metallic valve 6 on thestem coacts with a valve seat on a larger rubber valve A, the lattervalve in turn, coacting with a valve seat B on the vent plug casing, asin my copending application, Serial No. 456,098, filed September 15,1954, of which this application is a continuationin-part and whichapplication has now matured into Patent No. 2,717,610, dated September13, 1955.

In both of the described structures, a heavy frustoconical, preferablylead, weight W rests when the battery is upright, upon an internal ledge7 of easing 5. Tipping of the casing, in any direction tips the weightfrom its seat upon ledge 7 and causes a valve head 6 of my improvedvalve stem to be drawn toward seat 9 of casing 5, or toward a seating onvalve A in Fig. 2.

The valve stem which comprises the essence of this invention andapplication is a two part stem, to wit, an upper rubber part 11 and alower metallic part 12. The term rubber is used in its generic sense andis intended to include any other substance having the desiredflexibility, elasticity and extensibility as natural rubber. Neoprene isone artificial product which may be used. The metallic part of the stemis preferably of stainless steel of an acid proof and non-corrosivenature. It comprises the valve head 6, slender rod-like stem 14, topprotuberant head 15 and an intermediate abutment 16 that is preferablycircular in form and presents a fiat, upper face. The weight W has anaxial channel 17 formed through its upper portion which extends from thetop of the weight to the top of an underside cavity 18 formed in saidweight and the presence of which cavity tends to raise the center ofgravity of the weight. The rod-like upper portion 11 of the rubberportion of the valve stem carries a pair of in tegral rubberenlargements 19 and 20, constituting abutments sufiiciently larger indiameter than the channel 17 to function to respectively engage over thetop of the weight and beneath the material of the weight at the top ofcavity 18. When the rubber stem is molded in manufacture an elongatedintegral rubber cord 21 is left attached to it. In assembling the devicethis rubber cord is passed upwardly through channel 17, drawing thesomewhat pointed upper abutment 19 and the rest of the stem with it.

When abutment or enlargement 20 engages the top wall of cavity 18 thelower part of the stem is brought to a stop. A further pull upon therubber cord slightly stretches that portion of the stem between theabutments 19 and 20 until 19 clears the channel 17 and springs outwardlyover the top of the weight. Then the pull on the cord is released andthe weight is left elastically bound between abutments 19 and 20. Afterthis the rubber cord is cut off. The upper portion of the rubber valvestem is solid. Its lower portion is formed with an internal channel 22into which the upper part of the metallic part of the stem is thrustuntil its abutment 16 is engaged with the lower end of the rubberportion of the stem. The protuberant head 15 will then be grasped andretained by the natural elasticity of the rubber, the channel 22 beingonly about the diameter of the lower portion of the metallic stem. Thus,the rubber will be distended by the presence of the head and the headwill be grasped and retained by the said rubber portion. The portion 11of the rubber portion of the valve stem must be of such size as toprovide sufficient strength to support the weight when the device iswholly inverted and it must also be of suflicient diameter to receive,embrace and house the upper portion of the metallic part of the stem. Atthe same time, though, the rubber portion should be readily bendable(see Fig. 2) so that movement of the weight out of arial alignment withthe casing will not cause so strong a tendency of the metallic stem andits valve, to move sidewise, as to cause cocking or binding of the valvewith respect to its seat. It is clear that the degree of readiness ofrubber stem to bend will be, in part, determined by the distance betweenthe point at which the rubber portion 11 leaves the bottom of the weightand the head 15 of the metallic part of the stem. Since the first namedpoint is at the top of cavity 18 and since this point is materiallyabove the plane of the bottom of the weight and the seat from which theweight tips, it follows that the formation of said cavity 18 in thebottom of the weight not only raises the center of gravity of the weightto render it more sensitive to tipping influences but also materiallyincreases the effective length of the bendable portion of the rubberpart 11 of the stem. This permits desirable ease of bend with resultantlessened tendency for the metallic stem to foilow the tipping movementof the Weight.

The arrangement described protects that part of the stem which lies inchannel 17 from contact by fumes or acids from the battery and thus longlife of the connection between weight and stem is assured. The metallicparts themselves are acid proof under the conditions i 3 of use. Thedescribed arrangement permits quick assembly of the parts by unskilledlabor. The result is that marked economies in manufacture are bad. Theprojection of the upperportion of the elongated metallic stem, upwardlyinto the lower part of the rubber portion, renders the lower part of therubber portion; rigid. Thus, the rubber portion of the stem presents astructure that is, though of rubber, rigid throughout a section of its 7lower part; is secured fixedly in the weight and embodies a bendablepart between the rigid part and the Weight. The lower rigid part aids inmaintaining axial alignment of the valve stem and the parts with whichit coacts to wit, seat 9 and valve A while the cavity 18 provides spacewithin which the bendable part may be disposed and act.

The invention is not limited to the precise construction set forth butincludes Within its purview whatever changes fairly come within eitherthe terms or the spirit of the appended claims.

Iclaim:

1. In combination a valve stem of the character described comprising arubber body portion anf a lower acid resistant metal portion, said metalportion comprising a valve head upon its lower end, a protuberant headupon its upper end and an intermediate abutment, the upper portion ofthe rubber body portion being solid and provided with spaced upper andlower laterally protuberant integral abutments, the metal portion aboveits abutment, entering and lying axially within the rubber portion withthe lower end of the rubber portion in contact with the upper face ofthe abutment of the metal portion of the stem.

2. In combination a valve stem of the character described comprising arubber body portion and a lower 7 acid resistant metal portion, saidmetal portion comprising a valve head upon is lower end, a prouberanthead upon its upper end and an intermediate abutment, the upper portionof the rubber body portion being solid and provided with spaced upperand lower laterally protuberant integral abutments, the metal portionabove itsabutment entering and lying axially within the rubber portionwith the lower end of the rubber portion in contact with the upper faceof the abutment of the metal portion of the stem, the lower portion ofthe rubber body portion of the stem being provided with a preformedaxial bore of a diameter to cause the rubber of the walls thereof tosnugly receive the upper part of the metal portion of the stem and to bedistended by the protuberant head to thereby grip and hold said head.

3. In combination a weighted tiltable body having an axial channelformed in the upper portion thereof which is open at top and bottom, atwo part valve stem comprising a flexible and resilient rubber part anda metallic depending stem, the rubber part being solid and extendingthrough the channel of the weighed body and being provided with spacedintegral protuberant extensions which extend laterally beyond and engagethe material of the weight at the upper and lower ends of the said axialchannel, the metallic portion of the stem having a valve upon its lowerend, a protuberant head upon its upper end and an intermediatetransverse abutment which has a flat upper face, the upper end of themetallic part of the stem lying within a preformed channel of the lowerpart of the rubber portion of the stem and with the lower end of thesaid rubber portion in contact with the upper face of the saidtransverse abutment.

4. In combination a weighed tiltable body, a two part valve stemcomprising a relatively thick, flexible and resilient upper portion ofrubber and a relatively slender, rod-like and acid-proof metallic lowerportion, means for securing the thick upper portion axially and againstmovement in the weight, with its lower part projecting downwardly belowsaid weight, the upper end of the rod-like metallic portion projectingupwardly into the lower end of the rubber portion, said metallic portionhaving a protuberant head upon its upper end, and an intermediatetransverse abutment against which the lower end of the rubber portionabuts, the protuberant head being resiliently gripped within the rubberportion whereby to resist endwise movement of the metallic portion withrespect to the rubber portion, said metallic portion carrying anenlarged valve forming member at its lower end the upper face of whichis shaped to engage a valve seat when the valve stem is pulled upwardlyunder the tipping action of the weight, the height .at which themetallic portion terminates within the rubber portion being at such amaterial distance below the point at which the rubber portion leaves theweight as to leave such a length of the rubber portion between the topof the metallic portionand the Weight that said rubber portion may bendwhen the weight is tipped out of axial alignment with the metallic part.

5. In a weight and valve stem assembly of the type in which thetippingaction of a weight draws an upwardly facing valve into engagementwith a valve seat, the combination with a tiltable weight having anunderside cavity extending a material distance above the lower edge ofthe weight; an elongated two part .valve stem and valve depending fromthe underside of the top of'the cavity said .weight' and comprising. anupper, relatively thick, elongated rubber portion of a length to extendwell below the bottom of the weight, means for securing said upperportion axially within said weight, an elongated slender, rod-like,lower portion of acid resistant metal having an enlarged valve forminghead a its lower end which head is shaped to present an upwardly facingvalve seat engaging portion, the upper end of said rod-like metallicpor-' tion engaging the lower part of the downwardly extending rubberportion to an extent to render the lower end of said rubber, portionrigid, means for securing the metallic portion to said rubber portionagainst endwise movement of the metallic portion with respect to therubber portion to thereby positively move the valve upwardly when theweight is tipped and downwardly when the weight moves toward uprightposition, the point at which the top of the metallic portion of thestem'terrninates, lying far enough below the point at which the rubberportion leaves the top of the cavity of the weight,

w to leave a substantial length of the rubber portion between saidpoints. that is capable of bending as the weight tips.

References Cited in the file of this patent UNITED STATES PATENTS

